our 6:00 newscast. >> it is explosive. coming up, "nbc nightly news." hope to see you back here at 6:00. ok and twitter. wx ctr projector & 65 screens interview set fo tonight, person of interest. police questioning a man in connection with the rash of random highway shootings after yet another car is struck by a bullet. without warning. scores of people killed when a giant crane comes crashing down at the largest mosque in the world. body slammed. newly released video of the violent moment a new york city police officer mistakenly took down former tennis star james blake. in a case reigniting the debate over excessive force. life saver. a major study out tonight on blood pressure. what you should start doing now to dramatically cut your risk of death. and stunning upset. serena williams in a jaw dropper losing her quest for sports immortality. and who is this 43rd-ranked

player who took her down? "nightly news" begins now. >> announcer: from nbc news world headquarters in new york this is "nbc nightly news with lester holt." good evening. i'm kate snow in for lester holt. it is the case that has gripped the phoenix area in fear for nearly two weeks now, and tonight there's a potential break in the investigation. police have detained two people calling one of them a person of interest in a series of random shootings, most along the busiest stretch of i-10. this new development coming on the same day as reports of yet another shooting. nbc news national correspondent miguel almaguer starts us off tonight from phoenix. >> shots fired. front driver's side windshield has a round shattered mark. >> reporter: today more emergency calls, more fear and frustration on the freeway. >> loud pops on the highway about ten minutes ago. >> reporter: swarming the shopping center, police tracked down an suv.

inside a person of interest. >> we're questioning one subject in association with our ongoing investigation. >> reporter: for the highway patrol it may be a rare break. over the last two weeks, there have been few leads. at least 11 vehicles struck by bullets or projectiles. windows shattered, lives threatened. >> it's been a long few days. it's really scary driving on the freeway. >> reporter: police think there could be multiple shooters. with shots fired day and night. >> i want all arizonans to remain alert and know that this is our top priority as the state government and as the department of public safety. >> reporter: today school districts rerouted buses. too risky to drive i-10. traffic may be down on the roadway, but it's up in this emergency call center. >> okay. so something hit your windshield? >> reporter: 911 is flooded. most reports of false alarms. as authorities monitor hundreds of traffic cameras looking for a needle in a haystack. >> it's frustrating but you've got to remember it's a

very difficult case to investigate. there's a lot of moving parts. >> reporter: tonight there's also a lot of highway to cover. the open road that for some feels and sounds like -- >> shots fired. >> reporter: -- the wild west. tonight police remain questioning one person who has been detaped, detained, calling that person a person of interest. authorities say they could be several shooters here, so they warn this case is far from being solved. kate? >> very scary. miguel almaguer in phoenix tonight. there are new mandatory evacuation orders tonight as an explosive wildfire rages out of control in central california. homes in danger of being consumed by flames as the fire also threatens to spread through an ancient grove of giant sequoia trees in kings canyon national park. nbc's gadi schwartz has the latest. >> reporter: in fire-ravaged california there is a new inferno growing called the butte fire, flames so intense, so

large, spreading so fast even a tv crew from nbc's sacramento station kcra was caught inside the blaze. nearby the heat is churning out swirling firenados. homes fully engulfed. explosions heard within. >> the fire's picking up and it's pushing up against the few containment lines we have so far. more evacuations are under way and families are ready to get out. >> just get the few things i need to take and god willing it subsides. >> reporter: the fire has grown to 50,000 acres in just three days. while near fresno the rough fire, california's largest fire, is now more than 119,000 acres. it's forced the evacuation of an exotic cat refuge. lions, tigers and jaguars loaded into crates. >> it's best to move the animals out at this point. >> reporter: the rough fire is also now expanding toward the ancient sequoia forests where we

climbed last week with scientists studying the effects of drought. one of the most remarkable things about the view up here, you get an overview of the forest. and unfortunately, a lot of the trees we see out there are dying because of the drought. >> reporter: sprinklers are being set up to protect the resilient redwoods, but in some areas up to 1 in 4 smaller trees have died. leaving dangerous levels of fuel. conditions where a tiny spark can quickly explode into unstoppable flames. during a historic fire season that has only just begun. gadi schwartz, nbc news, los angeles. there's been a terrible accident at one of the most holy sites in the world. a deadly crane collapse in saudi arabia at mecca's grand mosque. with more than 100 people killed, many more injured. images from the scene are still coming in tonight. we get late details from nbc's keir simmons. >> reporter: the terrifying moment caught on cell phone video. a towering construction crane

collapsing, then panic and calls for god's mercy. it came down on top of one of the most holy places in the muslim world, mecca's grand mosque, smashing through the ceiling just before evening prayer, causing carnage, too gruesome to show in full. at least 107 people were killed, more than 200 injured, saudi authorities say. men in bloodied robes, stunned simply to have survived. the mosque is surrounded by giant construction cranes. a powerful storm apparently caused the collapse. mecca had been hit by high winds and heavy rains. a view from above shows the base of the huge crane toppled. emergency workers flooding the area, carrying away the dead. they died on a holy day in a holy place, one believer said on twitter. "a martyr's death," said another. mecca is just days away from a huge influx of visitors. the hajj pilgrimage.

one of the largest religious gatherings in the world. last year 2 million people attended. security forces surround the area to keep it safe. but apparently what happened today was a terrible and terrifying accident, killing people who were simply here to praise god. keir simmons, nbc news, london. all week we've been seeing heartbreaking images out of europe. desperate refugees fleeing the war in syria, seeking a better life. the numbers are staggering. hundreds of thousands of people on the move. but every single family, every single child has a story to tell. our chief foreign correspondent richard engel reports now from hungary. >> reporter: carrying what little they can, a generation of syrian children is wandering through europe in search of a home. on the train tracks between serbia and hungary today we saw 4-year-old diana. her mother, rawa, a christian from damascus, tells

us she left syria so diana could have some hope of a future. and how many days have you been on the road, traveling? >> 15 days. >> reporter: 15 days? >> yes. >> reporter: and where have you been sleeping? >> on the streets. >> reporter: you've been sleeping on the streets? >> yes. yes. yes. >> reporter: in the cold and in the rain? >> yes. yes. >> reporter: and is it okay? has she gotten sick? or is she -- >> no. she's sick. >> reporter: volunteers gave diana food and water but no medical care. i asked diana if she's tired. "yes, from the rain and walking," she says. when she last slept in a bed? "long, long ago," she says. the hungarian police want the migrants to board a bus to be taken to a detention camp. while diana plays, her mother joins other grown-ups to decide whether to get on the bus or try to run away. if they run, they'll likely be chased by police, and rawa knows they won't get very

far. if they get on the bus, they'll be taken to a camp, perhaps put in a cage at the mercy of the hungarian authorities. a video of one camp shows police throwing food like feeding animals in a pen. but diana has a fever and rawa is in no condition to run. so they get on the bus, which takes them to a fenced-off camp. a generation of syrian children made homeless by war is landing on europe's shore every day. no one knows how many will ever find a home here. richard engel, nbc news, roszke, hungary. late word tonight in the race for president. rick perry is suspending his campaign. the former texas governor has been struggling in the polls and failed to build much momentum for his second bid for the white house. and while the crowded gop field just shrank by one, there is much buzz tonight about whether the democratic field will grow. after vice president joe biden gave his most

emotional remarks yet about whether he will run. nbc's peter alexander has more. >> you're better than i am. >> reporter: joe biden riding a wave of emotion, today observing 9/11 with first responders in new york. >> we always rise up as a nation. we always ride on. >> reporter: last night on "the late show" again confessing doubts about whether he has the heart for another presidential bid. >> nobody has a right in my view to seek that office unless they're willing to give it 110% of who they are. i'd be lying if i said that i knew i was there. >> reporter: biden still grieving the loss of his son beau to brain cancer. >> he said, "dad, i know how much you love me. so you've got to promise me somethin promise me you're going to be all right." >> reporter: even as sympathy

and support for a 2016 run grows. [ audience chanting "joe" ] >> be careful what you wish for. >> reporter: hillary clinton's lead is shrinking with both bernie sanders and biden gaining steam. a new national poll shows clinton beats her republican rivals including donald trump and jeb bush. ben carson, who's quietly surging, today met with community leaders in ferguson, missouri. >> we need to deemphasize race, and we need to emphasize respect. >> reporter: in a race already marked by surprises, in iowa scott walker's now dropped to tenth place after leading the field just a few months ago. trump and carson on top today. the billionaire joining the late-night circuit with jimmy fallon tonight. another shake-up. carly fiorina will join the top-tier candidates at next wednesday's republican debate. today taking a jab at trump. >> in the world i come from talk is cheap and actions speak louder than words. >> reporter: with rick perry bowing out it's worth noting that he was the front-runner this time four years ago before a bad debate performance, emphasizing just how much is at stake for these republicans heading into next week's debate. kate? >> how quickly things can change. peter alexander reporting tonight, thank you.

now to that epic upset that stunned millions of viewers across the country, bringing a lot of offices to a stop including our own newsroom during those final thrilling moments at the u.s. open. serena williams poised to make history. instead bowing out to an opponent most people thought didn't stand a chance against arguably the greatest player of all time. nbc's kristen dahlgren reports. >> reporter: for more than two hours an emotional williams battled to hang on to history. the world number 1 just two games away from winning the calendar grand slam. all four majors in the same year. but roberta vinci, a 32-year-old from italy ranked just 43 in the world, had other plans. >> i don't want to talk about how disappointing it is for me. if you have any other questions i'm open for that. >> reporter: williams wouldn't say the pressure got to her. >> i told you guys i don't feel pressure, i've never felt pressure. and i think -- i don't know. i've never felt that pressure to

win here. i think she played literally out of her mind. >> reporter: vinci has never won a set in the four times they've played. >> it's amazing. it's like a dream. >> reporter: for williams it was an exhausting week. she battled her sister venus on tuesday. after that match she admitted to being tired. >> i have to wake up early to practice, and i don't want to answer any of these questions and you guys keep asking me the same questions. it's not really -- you're not making it super enjoyable. >> reporter: for the crowds inside and outside arthur ashe stadium today every point seemed to come with heart palpitations. the end brought mostly heartache. >> i'm really disappointed. i felt like it was her game to win. >> reporter: but like serena herself -- >> i won four in a row. so pretty good. >> reporter: -- fans try to focus on what she has done. winning the so-called serena slam. four majors in a row. just not the same calendar year. >> she's still the

champion in my heart. i love her. we love her, serena! >> reporter: the reality out here, though, kate, is that ticket prices for tomorrow's final are plummeting. tickets that were selling for 1400 before today's match now going for less than half of that. >> ooh. kristen dahlgren at the u.s. open tonight. still ahead, life-saving new information about bringing down blood pressure and preventing heart attacks and strokes. what doctors have discovered. the results so exciting they ended a major study early just to get the word out. also our first look at the surveillance video of tennis star james blake tackled to the ground by an undercover police officer. a case of mistaken identity that has sparked an uproar.

there is important health news tonight that doctors are describing as a potential game changer in the way 80 million americans with high blood pressure are treated. the national institutes of health said today that more aggressively lowering target blood pressure would cut the death rate by a staggering 25%. nbc's tom costello has details. >> reporter: it's a significant contributor to two leading causes of death -- heart attacks and strokes. as many as 1 in 3 adults has high blood pressure. the systolic, or top number in the b.p. measures the pressure on the blood vessels when the heart contracts. up until now the target for anyone 50 and older was 140 or less. but today's study suggests getting that number below 120 could cut the risk of death by

25% and cut by a third the risk of cardiovascular events, heart attacks, heart failure and stroke. researchers say it will change the way doctors treat hypertension. >> this is huge. i mean, 25% less deaths and a third -- you know, 33% less heart attacks, strokes, and heart failure? that's huge. you don't get that lowering cholesterol. >> reporter: at brigham & women's hospital in boston jim mcgrath was seeing his doc today. with medication his bp has gone from 150 to 130. now it may need to go even lower. >> we've had a history in our family of having high blood pressure. nothing that would be critical or possibly terminal but you never know. >> reporter: in the federal study some people required two or more prescriptions to get their blood pressures down to 120. and blood pressure meds, especially in some senior citizens, can make them feel dizzy or light-headed and cause them to fall. still, doctors say this study suggests the benefits may far outweigh the risks. >> we've previously been a little bit more lax on controlling blood

pressure, but this study shows that we have to get people's blood pressure back to normal, and that will help them live longer. >> reporter: still, tonight researchers say patients should not change their current medication levels without first talking to their doctor. tom costello, nbc news, washington. we're back in a moment with the violent videotape that had the nypd apologizing to a former tennis star.

for the first time tonight we're seeing the moment an undercover cop wrongfully took down tennis star james blake. late today the new york city police department released the surveillance video of the violent takedown a day after the commissioner apologized to blake. we get more tonight from nbc's rehema ellis. >> reporter: tennis star james blake is outside a hotel texting when suddenly a plainclothes officer approaches and tackles him to the ground. the hotel surveillance video, released late today by the nypd, shows blake is arrested and

handcuffed. >> it shouldn't have happened. >> reporter: blake says police used excessive force. police say this was a case of mistaken identity. but the commissioner is investigating. >> was the force used appropriate? and the initial review we believe that it may not have been. >> reporter: police and the mayor have apologized to blake. today blake responded, saying "extending courtesy to a public figure mistreated by police is not enough. i am determined to use my voice to turn this unfortunate incident into a catalyst for change." james frascatore, the undercover officer, have had two previous excessive force lawsuits filed against him. he's on modified duty. now the 59 seconds of video for everyone to see, a critical element in this case. rehema ellis, nbc news, new york. when we come back, never forget. 14 years since the day that changed everything. ===take vo=== we're following

breaking news outside sacramento - a wildfire is threatening an entire town... hundreds of homes. =jess/take vo=== plus: the instagram video - causing controvery for san francisco police. =next close= the news is next. none of us will ever forget where we were on this day in 2001 as the worst terrorist attack in the u.s.

unfolded before our eyes. 14 years have passed since the events of 9/11, and today people all over the country paused to remember the nearly 3,000 lives lost. ♪ [ bells chiming ] every year we hear the names read out loud and it never gets any easier. >> steven paul chucknick. >> reporter: connor gavagan's father worked for cantor fitzgerald. we first told his story when he was born, one month after 9/11. now he's 14 years old. >> if i were to have one wish in this world, it would be to meet my dad. although i never met him, from what i have heard he was a great man. >> reporter: and in shanksville, pennsylvania there's a new ritual this year with the opening of a brand-new memorial, a wall of photos as the

centerpiece, 40 feet high, one foot for every life lost. our own pentagon correspondent jim miklaszewski was invited to speak, struggling as he recalled being at the pentagon 14 years ago today. >> it became a makeshift morgue. >> reporter: he honored the men and women on flight 93 who stopped their plane from hitting the nation's capital. >> while all of us were writing only the first page of 9/11 history, the 40 on flight 93 were writing their enduring legacy. >> reporter: ed root's cousin lorraine bay was the senior flight attendant on board. >> the wounds never completely heal. we go on, we adapt, we do the best we can. >> reporter: for some it was a day of service, a day to pause and reflect in silence. 14 years have passed. it seems like yesterday. america will never forget. and that is "nightly news"

on this september 11th. i'm kate snow in for lester. for all of us at nbc news, thank you for watching. have a good night. we begin with breaking news just southeast of sacaremnto ... this is esentially gold country... a wildfire that breaking news is southeast of sacramento, gold country. a wildfire there raging out of control. it has grown exponentially in just the last few hours. about an hour ago mandatory evacuations were lifted for san andreas. people were told to be ready to get out if necessary again. the governor has declared a

state of emergency for this area. it is hot, it is dangerous. and that entire area has about 6,000 homes that at one point or another have been threatened by this fire. at this point it is only 10% contained. earlier this afternoon it started to explode and move in every direction, motivated by the wind. of course we're going to continue to monitor the situation here. good evening, everyone. i'm jessica aguirre. >> for the first time ever publicly, one of the seven students who survived that balcony collapse in berkeley is sharing his story. >> the group of friends hanging out on their balcony when suddenly it fell, killing six. today neil murray spoke to reporters outside t